Removal of volatile aromatic contaminants from wastewater by cloud point extraction

Removal of the aromatic contaminants benzene, toluene, and ethylbenzene from wastewater was investigated using cloud point extraction (CPE). A nonionic surfactant, t-octylphenolpolyethoxylate, was utilized as the separating agent. When the nonionic surfactant solution is heated above the cloud point temperature, phase separation is induced. The micellar-rich phase or coacervate phase and the micellar-dilute phase are formed. The aromatic contaminants tend to solubilize into the micelles and concentrate in the coacervate phase. The concentration of the solutes in the coacervate increases as temperature, added electrolyte concentration, and degree of alkylation of the aromatic solutes increase.